Science · 2014 · 881 citations · 39 references
Life SciencesNeurobiologyNeuroscienceSensory NeuroscienceVisual NeuroscienceVisual PerceptionGabaergic SignalingVisual NeurobiologyVisual NeurophysiologyVisual PathwaysVisual PhysiologyVisual SystemCortical Sensory ProcessingLocal MicrocircuitsLong-range ProjectionsOptogenetic ActivationPrimary Visual Cortex FunctionVasoactive Intestinal Peptide SignalingVisual Cortex PhysiologyVisual Signal Processing
Top‑down modulation lets animals prioritize task‑relevant sensory inputs. Cingulate cortex projections to V1 activate local GABAergic circuits, enhancing V1 responses, improving visual discrimination, and producing center‑surround modulation through distinct interneuron types.
Top-down modulation of sensory processing allows the animal to select inputs most relevant to current tasks. We found that the cingulate (Cg) region of the mouse frontal cortex powerfully influences sensory processing in the primary visual cortex (V1) through long-range projections that activate local γ-aminobutyric acid-ergic (GABAergic) circuits. Optogenetic activation of Cg neurons enhanced V1 neuron responses and improved visual discrimination. Focal activation of Cg axons in V1 caused a response increase at the activation site but a decrease at nearby locations (center-surround modulation). Whereas somatostatin-positive GABAergic interneurons contributed preferentially to surround suppression, vasoactive intestinal peptide-positive interneurons were crucial for center facilitation. Long-range corticocortical projections thus act through local microcircuits to exert spatially specific top-down modulation of sensory processing.
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A mesoscale connectome of the mouse brain
Seung Wook Oh, Julie A. Harris, Lydia Ng et al. · Nature · 2014 · 2.9K citations · Full text